HATCHING AND REPRODUCTION OF THE POTATO CYST NEMATODE, GLOBODERA-ROSTOCHIENSIS, FROM POTATO FIELDS IN WESTERN-AUSTRALIA AS INFLUENCED BY SOIL-TEMPERATURE

The optimum hatching temperature for the Western Australian population of Globodera rostochiensis was 22-degrees-C in picrolonic acid with a maximum total hatch of 88 +/- 6% after 42 days. In pots, under conditions simulating temperatures at the infestation sites, there were two peaks of hatching at 10-40 days and 110-140 days. Females and their eggs were first observed in the roots at 35 and 49 days respectively with most males in soil at 60 days. No second generation of eggs was observed following the second peak of juveniles in soil. Females on plants transferred from 15/10-degrees-C at 35 days after sowing developed between 5-30-degrees-C but the optimum temperature for egg development was 15-degrees-C. The relationship between initial and final egg density was as reported previously.